SA4023: reformat link in documentation

This works around a limitation in Hugo's markdown processing that
includes the closing parenthesis in the URL.

Closes: gh-1614

staticcheck/sa4023/sa4023.go

@@ -79,7 +79,7 @@ Similar situations to those described here can arise whenever
 interfaces are used. Just keep in mind that if any concrete value
 has been stored in the interface, the interface will not be nil.
 For more information, see The Laws of
-Reflection (https://golang.org/doc/articles/laws_of_reflection.html).
+Reflection at https://golang.org/doc/articles/laws_of_reflection.html.
 
 This text has been copied from
 https://golang.org/doc/faq#nil_error, licensed under the Creative